Conventionally, an absorbent article such as a disposable diaper is generally manufactured by using a manufacturing line in which an absorber and an elastic member (for example, a polyurethane fiber) are arranged sequentially on a continuous web conveyed by a belt conveyor, for example, and the manufacturing line includes a step of folding and a step of cutting the continuous web.
In order to check the manufacturing status of an absorbent article thus manufactured through a plurality of steps, an imaging system in which a camera is installed at a plurality of positions on the manufacturing line, and real-time images of the absorbent article being manufactured are acquired is known (for example, PTL 1). According to such an imaging system, if a failure location exists in an absorbent article being manufactured, the existence of the failure location can be detected promptly.